The present invention relates to a semiconductor device and a method of manufacturing same, which are suited for use, for example, in a semiconductor device using a nitride semiconductor.
Semiconductor devices using a compound of Group III-V having a band gap larger than that of silicon (Si) have recently attracted attentions. Among them, MISFETs (metal insulator semiconductor field effect transistors) using gallium nitride (GaN) are advantageous from the standpoint of large dielectric breakdown field, high electron saturation velocity, high thermal conductivity, ability of forming a good heterojunction between AlGaN and GaN, and use of a nontoxic and therefore highly-safe material.
For example, Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2006-245564) describes that by making the long direction of a channel of a FET having an AlGaN/GaN heterojunction parallel to the C-axis direction of a hexagonal crystal, generation of piezo charges in a channel region which will otherwise occur due to formation of a gate electrode can be suppressed.